Piston for engines



March 23, 1937. R, G FRYE 2,074,581

PISTON FORENGINES Filed Ja'n. 6, 1954 ik mim/1 Eig. L

Jnvenfor l, ARUBERTGJRYE Patented Mar. 23, 1937 UNITED NSTATES PATENT OFFICE PISTON` FOR ENGINES Robert G. Frye, Norwich Township, Franklin County. Ohio Application January s, 1934, serial No. 'roasts 2Claims.

'I'his invention relates to pistons for engines and'more particularlyto the species in which the i piston is reciprocated in a cylinder to drive a of the cylinder becomes ellipsoidal thus result-` ing in gaps forthe passage of gases and oil. The

only remedy in practice for such a condition has been a reboring of the cylinder and the provision of new piston or ring of larger diameter.

Various means have been proposed for compensating or minimizing such wear, and-the principal object of my invention is to provide an improved construction wherein such wear, especially 'in the zone of travel of the piston head, is so far avoided as to be practically negligible. Other objects incidental to the principal one will appear from the disclosure.

My invention is embodied in the example and' 5 modication herein shown and described, .the

feature of novelty being ilnally claimed.

In the accompanying drawing- Figure 1 is a view mainly in central section of one embodiment of the invention.

Fig. 2 is an elevation" looking at the right hand side of Fig. 1 with a portion broken out.

Fig. 3 is a cross section on the line III-111 Fig. l, looking down, the wrist pinbeing in pull.

Fig. d is a side elevation of a piston head having standard rings with my' guide ring applied.

Inthe views the character Il designates the body of the piston head, said head being made with an annular groove II, parallel faces forming.

ward. Fitting in said groove and on saidlip is an internally hollowspring ring I2 having slant-l ing legs, the upper ofwhich laps on theaforesaid upwardly and outwardly slanting lip of the piston head when the ring is applied thereto as shown.

The head portion of the piston is provided with opposeddiametrical seats for a pin I3 which is lieldA from longitudinal protrusion on said seats by a spring ring Il. 'I'he piston head is providedhug the wall of the cylinder in the reciprocations of the piston and aid in preventingleakage.

The lower end of the piston head is provided with an annular groove I1 in which is fitted the upper leg of another spring ring I8, the latter being provided with a vacuum groove I9 extending therearound thereby producing a tendency of the ring to hug the cylinder wall.

20 designates the skirt member, it being a distinct structure separable from the head member but having a swinging connection with said head member. The skirt member 20 is provided with a wrist pin 2I. The swinging connection between the `piston skirt and head member consists of link-like member or members 23,v 23, each having bosses fitting on the wrist pin of the skirt member and the pin I3 of the head member.' The link-like members 23, 23 are spaced apart at their lower ends to provide room for connecting therewith of one end of the connecting rod 24, said connecting rod being connected, as usual, at its other end with the crank shaft (not shown) of the engine. The pin I3 is longitudinally parallel to the pin 2l. j From this construction it will be observed that the side pressure of the pulland push of the connecting rod is borne by the comparatively long skirt and not by the head member of the 4piston because said head member being pivoted to the pin of the skirt 'member is merely guided by the wall oi lthe cylinder. Moreover because the pin I3 is longitudinally parallel to the wrist pin 2l the direction of the thrust of the skirt member is parallel to and not crosswise of the axis of the pin I3 hence the lateral pressure of the thrust or pull is net communicated in a direction transverse the pin I3 which would cause the head member to veer toward the wall of the cylinder.

The inwardly slanting U-shaped cross section of the piston ring fitting in a similarly slanting groove and on the lip at the top of the piston head as shown in Fig. 1 favors the prevention of pressure, gas and oil leakage 'past the rims oi' the rings because when the explosion takes place pressure tends to be exerted on the upper leg oi.'

the ring to close it 'on` the top of the piston head and excessive pressure onI the cylinder wall by the ring is lessened because the lower leg rides on the inclined wall of the groove containing said lower leg. In other words both legs of the piston ring in all positions hug the lip on which the ring is placed. Also when said upper legis slanting upward and outwardly, theexplosion pressure tends r to force said ring outwardly toward and into `contact with Athe wall of the cylinder thereby increasing the sealing eiect.

However the principal features of the invention can be embodied in a construction in which the head portion is provided with ordinary rings such as shown at 33 in Fig. 4. t

The forms of theV parts can be changed without departing from the gist of the invention as claimed.

What I claim is:

l. A piston having at the top of its head portion an annularly and upwardly and outwardly flared lip, said lip bounding an annular groove below said lip .and groove, said lip and groove each having parallel faces and a piston ring oi' generally U-form in cross section having parallel legs tting and sliding on both 'sides of said lip and in said'groove.

2. A piston including a skirt portion and a head portion having piston rings at its top and bottom, a wrist pin in said skirt portion, and a transverse pivoting pin in said head portion mounted substantially centrally in said head portion between the piston rings thereof, said wrist pin and the pin of the head portion being longitudinally parallel to each other, and link means connecting said pins.

ROBERT G. FRYE. 

